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Claude 2.1 vs o1-pro

Anthropic Claude 2.1 vs OpenAI o1-pro — side-by-side specs.

Anthropic
Claude 2.1
OpenAI
o1-pro
Overview
CompanyAnthropicOpenAI
Release dateNov 21 2023Mar 19 2025
Model type
Open sourceNoNo
Specifications
Parameters
Context window
Benchmarks
Timeline
Release gapClaude 2.1 shipped 484 days before o1-pro

Which is better: Claude 2.1 or o1-pro?

Claude 2.1 and o1-pro don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. Claude 2.1 shipped 484 days before o1-pro, so benchmark comparisons should account for the intervening progress.

Published specifications for these two models are limited — see each model page for the latest details.

Direct benchmark comparisons are unavailable — Claude 2.1 and o1-pro don't publish scores on any of the same benchmarks.

Frequently asked questions

When was Claude 2.1 released?
Claude 2.1 was released by Anthropic on Nov 21 2023.
When was o1-pro released?
o1-pro was released by OpenAI on Mar 19 2025.

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